fix(deps): update dependency org.openapitools.openapidiff:openapi-diff-core to v2.1.6 (#6923)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

pom.xml

@@ -227,7 +227,7 @@
     <jackson-dataformat-yaml.version>2.18.2</jackson-dataformat-yaml.version>
 
     <!-- OpenAPI -->
-    <openapi-diff.version>2.1.5</openapi-diff.version>
+    <openapi-diff.version>2.1.6</openapi-diff.version>
     <!-- We need to manually include the version because of dependency issues with snakeyaml -->
     <swagger-parser-v3.version>2.1.36</swagger-parser-v3.version>